The invention relates to a method of removing yarn residues from tubes on which such yarn residues are found and to an apparatus for carrying out the method.
The tubes have the configuration of hollow bodies. Because of their function, they are also known as yarn bobbins. They are a conventional means for the temporary storage of a thread which is provided for example as yarn or twist. The thread can easily be unwound from the bobbin although in the unwinding process, thread residues remain on the tube. The amount of the thread residue remaining on the tube varies as a function of the textile machines in which the tube is used as well as the parameters of the unwinding of the thread. Indeed, while the major part of the length of the thread can be unwound residues will remain on the tube. The residual piece of thread can be individual thread segments but can also be some several hundred turns.
In a known process for the removal of thread residues the thread on the tube can be cut at least once substantially through all turns.
The thread is cut with a suitable cutting tool, for example a blade. In this case there is, however, the danger that the tube will be damaged.
The invention has as its object to provide a method of the type described at the outset whereby the thread residues can be removed in the simplest possible manner.
The invention has the further object of providing an apparatus of the type described at the outset with which the process can be carried out.
According to the invention, these objects are attained and the process described at the outset is so carried out that at least a liquid jet is trained on the surface of the tube.
In an especially simple and advantageous mode of the invention in which the thread is cut by jet of a liquid under pressure, especially water, the nozzles are shiftable substantially parallel to the outer surface of the tube.
In this manner a constant angle can be maintained between the jet direction of the nozzle and the surface of the sleeve.
The subject matter of the invention is, in addition, an apparatus for removing thread residue from at least one tube which is so configured that it includes at least one nozzle which is so oriented that the liquid jet emerging from the nozzle is trained on at least one location on the surface of the tube.
Especially, the apparatus includes a fastening means which so holds one or more sleeves that one or more water jets can impinge directly on the surfaces of the tubes. The individual tubes are thereby preferably so mounted that the liquid, after impinging upon the surface of the tube or the surfaces of the tubes, can run off freely. Preferably the tubes during the process are received in a processing chamber containing normal air which optionally can contain water vapor from the water jets.
The water jet can have sufficient pressure for cutting through the thread and preferably so selected that the surface of the tube is undamaged.
The water jet can have a thickness which is substantially smaller than the surface of the tube.
For example the water jet has a thickness of several mm2, or cm2, while the area of the tube can be substantially greater.
It is especially advantageous that the water jet be so directed that it impinges on various impingement points which differ from one another on the surface of the tube. It is especially advantageous that the water jet be so directed that the impingement points form a continuous line.
The apparatus can include at least one nozzle which is so oriented that the liquid jet which emerges from this nozzle is directed at least against one location on the surface of the tube.
The nozzles can be shiftably mounted substantially parallel to an outer surface of the tube.
It is especially advantageous that the nozzles be shiftably mounted substantially perpendicular to the travel direction of the thread.
It is especially advantageous that the jet nozzle be so mounted that they have a jet direction in which the jet impinges on the surface segment of the tube turned toward the nozzle at an angle between 25xc2x0 and 75xc2x0, advantageously between 35xc2x0 to 45xc2x0.
As a result there is an effective displacement of the thread from the cutting zone with simultaneous avoidance of an excessively high liquid pressure on the surface of the tube.
It is especially advantageous that the nozzles be mounted to be shiftable substantially parallel to the travel direction of the thread. As a result a straight cutting line is achieved.